Field of the Disclosure
Certain aspects of the present disclosure generally relate to wireless communications and, more particularly, to sounding procedures for generating and feeding back channel information.
Description of Related Art
Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, etc. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Examples of such multiple-access networks include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks.
In order to address the desire for greater coverage and increased communication range, various schemes are being developed. One such scheme is being developed by the Institute of Electrical and Electronics Engineers (IEEE) 802.11ax task force. This development is driven by the desire to combine the spatial diversity gains achieved with multiple in-multiple out transmissions using multiple antennas with orthogonal frequency division multiplexing schemes, with subsets of frequencies assigned to different users.
To take advantage of these schemes, channel information across both spatial streams and different frequency regions may need to be fed back from stations to allow an access point to optimize performance. This feedback may be obtained through a sounding procedure, whereby a station generates channel information based on training fields in packets transmitted from the access point. During the sounding procedure, it may be desirable to limit the amount of feedback while still ensuring adequate performance.